Identify the primary purpose of an optical amplifier in a communication system.

The primary purpose of an optical amplifier in a communication system is to boost optical signal strength without converting it into another form of energy. This amplification is crucial for overcoming losses that occur during signal transmission over long distances in optical fibers. By enhancing the strength of the light signal directly, optical amplifiers maintain the integrity and quality of the signal, allowing for clearer communication over longer ranges.

In contrast, other mentioned functions do not align with the primary role of optical amplifiers. Stabilizing signal amplitude would imply a modification of the signal rather than pure amplification. Filtering involves removing unwanted wavelengths rather than amplifying them. Converting light signals into radio waves pertains to a different technology primarily involving modulation and does not reflect the optical amplification process. Therefore, boosting the optical signal while retaining its original form is clearly the focus of an optical amplifier in communication systems.